What Emo Is And Some History.
Emo is short for emotive hardcore. It's a DIY music style (not a shitty fashion) that started in the 80's. Emo follows (but is not restricted to) the lines of hardcore. Hardcore is a subgenre of punk, therefore, so is emo. The first emo band is often credited to Rites Of Spring. They played with hardcore punk rock energy (as the members were previously involved with hardcore bands) and lots of emotion through their performance and with their audience. Their lyrics seem to have important views about life and a sense of deepness.

"Emo" As A Term.
The term "emo" was generated as an insult to people in the hardcore scene that liked these bands. An emo band's performance on stage (can include crying/moaning/etc. their lyrics and various other events) probably made them look "weaker" to the hardcore kids, which is (why I think) "emo" was directed as an insult.

What Screamo is.
Screamo has evolved from emo. This music style invloves more screaming and often has more melodic breakdowns. Screamo is still emo, therefore follows its guidelines.

What Emo Is Not.
Emo is not short for emotional. Emo is not a fashion. Emo is not "XxXxXxXOMMMFFGZZZZ IM LYKE, SO DEPRESSED!XxXxX!!!1!!111 IM GONNA SLIT MY WRISTZZZZZZZ...LOL..XxXxXxX" Emo was not mainstream (because it was DIY). Emo has nothing to do with being depressed, shitty metaphors, or suicide. Emo is not whiney, bullshit music sung by pubescent males that haven't dropped their balls yet.

-Emo music: Stands for 'emotive hardcore' music and branched off from 'hardcore music' (a heavier faster version of punk). Emo is characterized mostly by its vocals. The male singer often sounds femenine. There may be moans, screams (as opposed groans or roars), and simply singing in a very soft manner. Lyrics also play role. These are mostly characterized by complaints or discussing stressful life situations.

-Emo as slang or an insult: Invented by opposers to the emotive hardcore style and music. More fundamental 'hardcore kids' wanted to distinguish themselves from the emotive hardcore genre or emotive hardcore listeners, so they attached an offensive nature to the term 'emo' (which was short for the music) and invented the term 'emo kid.'

-Later use: Emo became associated, as an insult, with introverts who had thick rimmed glasses, shaggy hair, old band shirts, depression, and self mutilation.

-Today: People defined as emo today, are mostly part of the emotive hardcore scene. People who follow the popular emo fashion style (described below) may also be labeled emo, even though they do not enjoy the music or the scene.

-Contemporary Emo Fashion style: Both the males and females are characterized by having hair in their face (sometimes spikey in the back and/or with highlights), a lot of makeup, tight jeans, piercings (especially ones called 'snakebites'), and more. Female styles include: fake pearl necklaces or other 'loud' necklaces, bows or clips in the hair, ballet-flat shoes, very large sunglasses, clothing with polkadot patterns, and more. Male styles include wearing female clothing such as small shirts or jeans, painted nails, converse, and more.

-Defensiveness: Today, many people in the emo scene (where people gather to listen to emotive hardcore) and elsewhere are very offended by the term 'emo.' They will claim to be 'scene' or 'scenesters' instead, or they will attempt to claim they are 'simply individuals' and do not follow any certain label or trend.

-Emo in Pop Culture: The emo culture has become ubiquitous in every day life. This is mostly due to Myspace, where the music and the style are extremely popular and even often picked up by young children who have no idea the music or scene exists. Its popularity is also due in part to MTV for popularizing bands that take most, if not all, of their fashion style and music style directly from the emo scene (such as Fallout Boy or MCR). And again, emo scene kids will get defensive about this fact and declare that those bands, or any band that becomes popular enough, either 'sucks' or are not true emo bands but instead 'pop punk', among other terms.

First off, ignore what all the emo purists say. According to them, emo is hardcore punk with emotive lyrics, and according to them, any band that has long bangs on their hair covering the sides and back or their fans look like that and have lip rings, jeans or something "can't be emo". They also think all emo bands have short hair and look like a hardcore punk band. Even some bands they reject as emo sound like the bands they call emo. (Dashboard confessional sound like 90s emo alt rock; MCR used to sound 80s emo; senses fail sound old school; etc) Emo basically is shortened as emotional. But it usually derived from alternative and punk. Nowadays many bands are gonna sound post-hardcore, indie, alt rock, and stuff. Emos as persons like this music, and also they might express emotion. But emo kids started to come more in 2004 and then started having a hair fringe and hair covering their head (except the face, they don't have to), jeans, band shirts or sometimes lip rings and studded belts and stuff. Screamo, though as hardcore punk influenced but had screaming and was intense. Even screamo gets confused with metal or even certain "Core" genres. Only certain core bands are emo as long as they have roots tracing from like The Used, MCR, or Hawthorne Heights or silverstien or something

i'm emo....and i don't cut, i don't cry over everything, emo boys r not gay, and don't wear girl pants. see there used to be the truth about emo but then all u haters started hearing weird crap.i don't like to listen to sad depressing music all the time and infact i like lots of happy music...but u wouldn't know that...cuz you think we are just fags with bad taste. well sry u guys...but we are just more popular nerds...not people who are trying to destroy the world. (thats how u emo haters make it sound like...like we're making you die or something) and i just can't get why all u haters take ur time to talk shit about us....wat did we do to you? i say just get over...pick on some other label for a change. and yea..i'm taking my time to do this just cuz maybe i can change ur mind. cuz i'm sick of it.